World News Update, what you need to know

A new Boko Haram massacre has killed hundreds in Nigeria, with police offering a 50 million naira ($A324,600) reward for information leading to the rescue of more than 200 schoolgirls held hostage by the Islamists.

ELSEWHERE:

JOHANNESBURG - Millions of determined South Africans - including hundreds of thousands of first-time "born free" voters - have turned out in force for a landmark general election.

WASHINGTON - The US has called for a "peaceful" resolution to political tensions in Thailand and new elections after the country's constitutional court dismissed the prime minister and nine ministers for abuse of power.

WARSAW - NATO says it has seen no sign of Russian troops withdrawing from the border with Ukraine, despite President Vladimir Putin's claim they have been pulled back.

WASHINGTON - Federal Reserve Chair Janet Yellen says the US economy is pulling away from its winter freeze but is warning of risks from the Ukraine crisis and a real-estate slowdown.

SEOUL - The number of survivors from a fatal South Korean ferry accident has been reduced by two with authorities saying they miscounted the numbers of living and missing.